DOI: 10.4324/9780415249126-L142-1
Version: v1,  Published online: 2003
Retrieved June 04, 2020, from

3. Technical problems

Before CNR can be successfully employed in any of the applications described above, the following technical problems (as well as cost) must be resolved.

  • Scarcity of oocytes. Oocytes are a very scarce resource much in demand for treatment of infertility: currently 12–13 oocytes are needed to create a single embryo through CNR.

  • Genetic makeup. The embryo created by CNR would not be genetically identical to the nucleus’ donor, as it will inherit the mitochondrial DNA from the oocyte donor. The implications of this in terms of immunological compatibility are unknown. This may also have unknown implications if CNR is utilized in the treatment of mitochondrial disease.

  • Development of cloned stem cells. It is unclear whether stem cells produced by CNR would develop and age in the same way as stem cells produced by ‘natural’ or artificial fertilization (DOH 2000: 26).

  • Behaviour of cloned stem cells. It in unknown whether, once the stem cells derived by CNR were transplanted into the recipient, they would behave normally, whether they would be able to function normally and to integrate with the other cells in a normal way. The main risk is that they may give rise to tumoural formations (DOH 2000: 26).

  • Long-term safety. The long-term safety of transplants of tissues derived by CNR is unknown.

  • Purity of the tissues. At present almost all stem cells have been grown on a culture medium which is derived from animals. This would present dangers if the cells were used in therapy for humans. Until a safe culture medium for growing stem cells is established, human therapeutic applications will be for the most part too dangerous to contemplate.

  • Illnesses of the donor. The somatic cell from which the nucleus is taken may carry the genetic defect for which the person is being treated, although genetic engineering could in theory help to overcome this problem.

  • Large-scale production. There are the challenges of production of stem cells by CNR on a large scale.

  • Fetal abnormalities. With regard to the reproductive use of CNR, a high risk of abnormalities in foetuses and high premature mortality is registered.

Citing this article:
Harris, John and Simona Giordano. Technical problems. Cloning, 2003, doi:10.4324/9780415249126-L142-1. Routledge Encyclopedia of Philosophy, Taylor and Francis,
Copyright © 1998-2020 Routledge.

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